<script>
    let x1 = 10;
    console.log(x1 += 5);    //相等于x = x + 5
    
    let x2 = 10;
    console.log(x2 -= 5);    //相等于x = x - 5

    let x3 = 10;
    console.log(x3 *= 5);    //相等于x = x * 5

    let x4 = 10;
    console.log(x4 /= 5);    //相等于x = x / 5

    let x5 = 10;
    console.log(x5 %= 5);    //相等于x = x % 5
</script>